Tuned absorbers include a tuning mass suspended on a spring member and absorb vibration of the member they are attached to. They are resonant devices and their natural frequencies are generally tuned to coincide with a predominant disturbance frequency of the vibrating member. Examples of tuned absorbers may be found in U.S. Pat. Nos. 3,388,772, 3,490,556, 3,668,939, 4,230,291, 4,697,781, 4,852,848 and 5,052,530. Tuned absorbers including a pivot are found in U.S. Pat. Nos. 3,767,181 and 5,072,801.
Various methods have been used in an attempt to reduce vibration in pipelines. For example, U.S. Pat. No. 5,193,644 to Hart et al. entitled "Pipeline Vibration Absorber," which is hereby incorporated by reference herein, describes a pipeline vibration absorber 22 including a mass 32 interconnected to the pipeline 10 by a damper member 23 which includes an elastomer 34 and spaced apart support parts 36. The assembly 22 is connected to the pipeline section 10 via a clamp assembly 14 including semicircular straps 16 and bolts 18. These systems, although they function adequately, undesirably hang from beneath the pipeline where they are easily tampered with. Moreover, because they hang below the pipeline, their operation may be interfered with by brush growing or snow buildup underneath the pipeline. Therefore, there is a need for a vibration absorber that includes a compact profile.